AES San Francisco 2008Audio Product Design Event T6

Friday, October 3, 2:30 pm — 3:30 pm

T6 - Modern Perspectives on Hewlett's Sine Wave Oscillator

Presenter:Jim Williams, Linear Technology - Milpitas, CA, USA

Abstract:This tutorial describes the thesis and related work of a Stanford University graduate student, William R. Hewlett. Hewlett’s 1939 thesis, concerning a then-new type of sine wave oscillator, is reviewed. His use of new concepts and ideas of Nyquist, Black, and Meacham is considered. Hewlett displays an uncanny knack for combining ideas to synthesize his desired result. The oscillator is a beautiful example of lateral thinking. The whole problem was considered in an interdisciplinary spirit, not just an electronic one. This is the signature of superior problem solving and good engineering. Although the theoretics and technology are now passe, the quality of Hewlett's thinking remains rare, and singularly human. No computer driven “expert system” could ever emulate such lateral thinking, advertising copy notwithstanding. Modern adaptations of Hewlett’s guidance complete the tutorial. Handouts include Hewlett’s thesis, a detailed production schematic of the oscillator, and modern versions of the circuit.